Looking Deeper Into Error Frequency

 I'm finding the data collection and analysis to be interesting.  So today I collected only error information and specifically if a point was lost to an error, what was that error.  If a point was won with a put away, then I didn't record anything unless it was the result of a pop up error.

As I think about it, I would like to have the frequency of each shot.  It's not very important to know that 16 volley errors occurred if there were 120 attempts, but vital if there were only 25 attempts.  If it were 25 attempts, then there is an area that needs some work, or volleys are being hit when a dink or something else is a better percentage shot.

 So the data design is still in flux.  I think I look at a single error type and gather some frequency information.  

The data here were from a couple of advanced games.  Certainly the data might be different for intermediate or beginner games. 

 Here is the table with percentages of total errors.  

 

Errors
Dink	Serve	Srv Ret	Gnd Str	½ Volley	Volley	Ovr Head	Speed Up	Pop Up	Position	Drop Shots	Net Winnr	Total
7	2	4	16	9	16	1	3	14	2	3	4	81
8.64%	2.47%	4.94%	19.75%	11.11%	19.75%	1.23%	3.70%	17.28%	2.47%	3.70%	4.94%

Some additional thoughts on the data...

These were collected from two games.  The style played was more of a hitters game than a dinkers.  There weren't a lot of over heads, nor lobs.  

Let me quickly go through the column definitions.  

Dink is a dinking error, might have hit it into the net or wide, also might have been due to not being able to return a good dink.  

Serve is a serve that was out. Srv Ret is a missed service return. 

Gnd Str is a ground stroke error, defined as a ball that bounced, but not a half volley.  

1/2 Volley is the short hop or half volley.  I don't remember a lot of attempts and this error looks to be fairly frequent error, aka a difficult shot.

Volley is a ball taken out of the air, might be at the KL or mid court. 

Ovr Head is an attempt at a smash or full tennis type over head.  There were not many in the games I watched.

Speed up is someone getting aggressive at the net.  This looks to be a low percentage shot -- I don't remember a lot of successful ones.

Pop Up - the shot that leads to a lot of winners and the bane of all players.  Certainly a frequent error, since it can be generated from any position on the court, usually hit by some already at the KL.

Position - I think of the game as one of being at the right place at the proper time, so a couple of points ended because a player was not in a good position.  The actual type of error could be anything.

Drop Shots were attempts at a third or other drop shot.  Not frequently attempted in the games looked at.

Net Winners - points that ended with the ball hitting the top of the net and still going over.  I was surprised how often they came up.

The total errors was the sum of all the items I recorded. 

 

A bit more discussion... Ground strokes, pop ups and volley errors lead the pack.  

A secondary area is dink errors and half volleys are about 10 percent, the first group about 20%.  

Assuming that these data are correct, a player wanting to improve should work on the ground strokes and keeping the ball low.  Half volleys are a subset of ground strokes and practicing with ground strokes ought to create a few half volley opportunities too.  So maybe warm up hitting long shots and not dinking.  A touch shot is easier when the muscles are warm and hitting tiny dinks is not going to warm up the bulk of the  muscle system.

That's about all I see in these data.  Any thoughts otherwise are welcome and any suggestions for different statistics are welcome too.  The next think I'm going to look at is picking up some frequency information about a couple of the error types.  Stay tuned!